Nelson, along with his brother and their parents, appeared on the long-running sitcom The Adventures of Ozzie and Harriet in the 1950s and 1960s. Late in the run of the series, Nelson directed several episodes. After the series' end, he continued acting, directing and producing. His most memorable 'break-out' performance was in the 1959 thriller The Big Circus, wherein Nelson played a disturbed, apparently homicidal 'troubled youth', while his last film appearance was in the campier Cry-Baby (1990). For his contribution to the motion picture industry, Nelson was honored with a star on the Hollywood Walk of Fame at 1501 Vine Street, on May 9, 1996.[2]

Nelson had two sons—Daniel Blair and James Eric—from his first marriage with June Blair, which ended in divorce, and adopted two sons and a daughter—John, Eric, and Teri—during his second marriage, to Yvonne Huston.[1]